Burglar alarm



June 16, 1925.

1,542,745 J. w. THOMPSON, JR

- aunemm ALARM Fild April 15. 1922 2 Sheets-Sheet 1 fauna W7 h m/9502?, .jz' 1 WITNESSES I I V A n,

June 16, 1925. 1,542,745

J. W. THOMPSON, JR

BURGLAR ALARM Filed April 15,. 1922 2 Sheets-Sheet 2 Q Thom v.50, J2?

' ATTORNEY wi'masts Patented June 16, 1925.

3 1g. .w. mp irs iwe, or DRAKEWILLE Iowa;

Application filed April 15, 1922! SeriaI N'o. 553,148.

T all whom it may concern:

Be it known that I, JOHN TV. THOMPSON, Jr., a citizen of the United States, residing at Drakesville, in the county of Davis and State of Iowa, have invented new and useful Improvements in Burglar Alarms, of which the following is a specification.

The object of this invention is to provide parts, to be hereinafter fully described,

illustrated in the accompanying drawings and specifically pointed out in the appended claim.

In describing my inventionin detail, reference will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which Figure l is a diagrammatic view of invention.

Figure 2 is a vertical sectional view of the device in operative position. Figure 3 is in an elevation partly insection of the latch means for holding the device in operative position, and Figure f is a perspective of one of the elements embodied in the invention.

the

In these views 1' indicates a casing which and which is preferably of square shape in cross section. A block 2 is placed in the casing and a cylinder 3 passes through the block with its upper end projecting from the block this end being screw threaded to receive a cap 4. The cylinder 3 is formed to receive an ordinary blank shot gun shell and the cap is provided with a firing pin 5 which is normally held in raised position by a spring 6. The cartridge is inserted after the cap has been removed and then the cap is replaced so that the firing pin will be over the cap of the cartridge. The lower part of the casing is provided with holes 7 for the escape of the gases. A rod 8 passes through a hole in the top of the casing, and a weight 9 is attached to the lower end of the rod,

this weight being adapted to strike the firing pin to press the same against the cartridge to explode the same. The weight is normally held in raised position by means of a trigger 10 which is pivoted to thetop of the casing and has its pointed end engaging a recess 11 in the rod 8. hen the trigger is moved out of the engagement with the red the weight will fall and thus explode the cartridge. In falling the weight will strike one end of a pivoted arm 11 which has its other end connected by a link 12 with the lever 13 of a knife switch 14:. Thus this switch will be closed by the falling weight so as to complete the circuitof the lighting system of the building or an alarm 15 which may be of any type and which may be located at any desired place.

A wire or other flexible connection 16 connects the cable with a bell crank 17 and other connections 18, which are secured to bell cranks 19, lead from the bell crank 17 to the windows and doors of the building, the connections which are fastened to the windows and doors being so arranged that when the window or door is opened the connections will be pulled so that the trigger will be released from the rod and thus permit the weight to fall upon the cartridge. The falling weight will also actuate the switch to close the electric circuit which may include the lights of the building so that these lights will go on and thus act to scare off the burglar. Of course an electric alarm may also be included in the circuit and this alarm may be placed in any desired position in the building or in another building.

The invention may be used in all kinds of buildings such as store's, public and private garages, ware houses and the like. i

It is thought from the foregoing description that the advantages and novel features of my invention will be readily apparent.

I I desire it to be understood that I may make changes in the construction and in the combination and arrangement of the several parts, pro ided that such changes fall within the scope of the appended claim.

lVhat I claim is A device of the character described comprising a casing, a casting arranged in the casing and provided with a bore, a cartridge holding tube arranged in the bore, a cap removably arranged upon one end of the cartridge holding tube, a spring pressed firing pin received in the cap andextending the casing and a pivoted latch carried by the casing and normally engaging the rod to hold the Weight in an elevated position, 10 and means for disengaging the latch from the rod to permit the Weight to fall.

In testimony whereof I affix my signature.

JOHN lV. THOMPSON, JR. 

